Download full final report - Northeastern States Research

Evolving niche of the “coy-wolf” in northeastern
forests and implications for biodiversity
Principal Investigators
Dr. Jacqueline Frair
Dr. Mark Teece
Roosevelt Wild Life Station, SUNY ESF
1 Forestry Drive, Syracuse, NY 13210
[email protected]
Collaborators
Stacy McNulty
Adirondack Ecological Center
Department of Chemistry, SUNY ESF
[email protected]
Paul Jensen
NYS Department of
Environmental
Conservation
Completion date: 3 May 2012
Funding support for this project was provided by the Northeastern States Research
Cooperative (NSRC), a partnership of Northern Forest states (New Hampshire, Vermont,
Maine, and New York), in coordination with the USDA Forest Service.
http://www.nsrcforest.org
Coyotes began colonizing the Northeast in the 1920s, and are the most abundant
large carnivore in the region today. We asked:
Project Summary
1) Are coyotes deer specialists, thereby filling the vacant niche of the
wolf rather than co-opting the niche of extant carnivores?
2) How much do coyote diets overlap native carnivores, and by what
means might they establish a stable coexistence?
We constructed a timeline of coyote diet from the 1950s to today, and related coyote
use of prey to changes in prey abundance. We documented dietary overlap among
coyote, bobcat, gray fox and red fox using stable isotope analysis.
Despite high use of deer, coyotes are not deer specialists. Rather, deer use
depends on the abundance of primary prey, specifically snowshoe hare (historically)
and beaver (currently). As coyotes increasingly exploit beaver populations, we
expect use of adult deer to continue to decline. However, use of fawns remained
constant despite primary prey availability, so if coyote numbers increase as a result
of abundant beaver then total predation on fawns may increase too.
Native carnivores appear sufficiently flexible to achieve a stable coexistence with
coyotes. Coyote, gray fox and red fox diets largely overlap, but fox coexist with
coyotes by exploiting predation refuges – gray fox by climbing trees and red fox by
occupying human-dominated areas. However, red fox use of human development
may become problematic if it leads to increased human-wildlife conflict.
Background
Coyote Range
• 1920s: following extirpation of wolves,
coyotes began colonizing the
Northeast
• Last 30 years: coyotes most
common large carnivore throughout
the Northeast
Pre-European
• Eastern coyotes share genes,
morphology, and (potentially)
behavior with wolves
• Ecological role of these “coywolves” of interest to scientists,
managers, and public
Present day
Moore and Parker 1992
Background
• Potentially large ecological impact
through:
– competition with native carnivores
(red fox, gray fox, bobcat)
– predation on deer and other species
• Requires study of drivers of prey
consumed by coyotes and dietary
overlap with native carnivores
H1 Deer specialist 
filling vacant niche of wolf
H2 Mid-sized prey specialist 
displacing native carnivores
Contemporary dietary
overlap with native
carnivores
Study Area
Long-term study of coyote
diets and its drivers
Methods – evolving coyote diet
1. Walk transects
4. Sort prey remains
2. Collect coyote scat 3. Dessicate then wash scats
5. Identify species by hair patterns
WT Deer
Snowshoe hare
Beaver
Red squirrel
6. Compare to past studies (1956-61, 1975-80, and 1986-89) and prey abundance
Methods – niche overlap
You are what you eat:
Stable isotopes in mammalian hair reflect
diet composition for period of hair growth
• Hair of Adirondack carnivores
acquired from registered fur trappers
• Nitrogen isotope (δ15N) reflects trophic
level (level of carnivory vs. herbivory)
• Carbon isotope (δ13C) reflects
photosynthetic pathway – Native
plants at one end and corn (human food
sources) at the other
Key Results
100
Deer adult
Deer fawn
Snowshoe hare
Beaver
Red squirrel
SUMMER
80
60
% 40
of 20
scats 0
with 100 WINTER
prey 80
item 60
↑ beaver/hare
↓ deer
↓ hare
↑ deer
40
20
0
1956-61
1975-80
1986-89
2009-11
(Hamilton 1974)
(Chambers 1987)
(Brundige 1993)
(Warsen 2012)
Coyote use of deer does not track
changes in deer herd
1000
Severe winters
High hunter harvest
100
Winter diet
90
900
Buck
harvest
(5-yr ave)
80
70
Summer diet
800
60
50
700
40
NY State
DEC
600
30
Forest maturation
set lower K
500
1960
1970
1980
Year
Source: Warsen (2012)
10
0
400
1950
20
1990
2000
2010
Deer
% of
scats
Coyote use of deer (secondary prey)
driven by availability of primary prey
35
30
25
20
15
Statewide
10
5
Adirondacks
0
1960 1970 1980 1990 2000 2010
NYS DEC
Source: Warsen (2012)
40
(Huntington Forest)
Snowshoe HareHarvest
(x 10,000)
Hare dominated
Deer
40
dominated
Active Beaver Lodges
Shifting to beaver
Deer
dominated
35
30
25
20
15
10
5
Foster et al. (2002) “Wildlife
dynamics in the changing New
England landscape”
0
1960 1970 1980 1990 2000 2010
SUNY ESF Adirondack Ecological Center
Niche competition
 Fish eaters highest on N axis
(longer food chains)
10.0
Otter
Region of greatest competition
9.0
Degree of 8.0
carnivory 7.0
(δ14N) 6.0
5.0
Mink
 Most
herbivorous
species (bear)
lowest on
N axis
4.0
-30.0
Source: Warsen (2012)
-28.0
Weasel
Marten
Coyote
Bobcat
-26.0
Red fox
Fisher Gray
fox
Raccoon
Black bear
-24.0
-22.0
Degree of human tolerance
(δ13C)
-20.0
Niche competition
9.0
Greatest use of
natural food sources
Greatest use of human
sources of food
8.0
Degree of
carnivory
(δ14N)
6.0
Red fox
Coyote
7.0
Bobcat
Gray fox
Greatest dietary
overlap with coyotes
5.0
4.0
-25.5
Fisher
-24.5
-23.5
-22.5
-21.5
-20.5
Degree of human tolerance
(δ13C)
Source: Warsen, Frair & Teece (2014), Isotopes in Environmental & Health Studies
-19.5
Implications
• Coyote not deer specialists, not filling niche of wolf
– Use of deer driven by primary prey, hare and beaver
– Increasing use of abundant beaver may increase coyote numbers
– Coyote use of adult deer likely to decline, but use of fawns stable
or potentially increasing with implications for herd productivity and
management
• Strong diet competition among coyotes and native
carnivores, but mechanisms for co-existence exist
– Tree climbers (fisher, gray fox) able to maintain traditional niche
– Red fox and bobcat may be pushed to diet/habitat extremes due
to coyote interference
– Red fox may find refugia in human-dominated areas, but that
might increase human-fox conflict
Future directions
• Mechanisms of red fox – coyote competition and potential
displacement currently under study at Fort Drum
• Continued long-term monitoring of coyote diets in
Adirondacks needed to evaluate importance of beaver to
coyote population dynamics and its implications for spillover predation on deer
Products
Peer-reviewed publications
Warsen, S.A., Frair, J.L., and Teece, M.A. (2014) Isotopic investigation of
niche partitioning among native carnivores and the non-native coyote (Canis
latrans). Isotopes in Environmental and Health Studies, DOI:
10.1080/10256016.2014.897946.
Warsen, S.A. and Frair, J.L. (in prep; anticipated submission fall 2015)
Evolving dietary niche of coyotes in the Adirondack Mountains of New York.
Intended for submission to Wildlife Society Bulletin.
Other publications
Frair, J.L., Gibbs, J.P., Batcheller, G., and Jensen P. (2014) Population status
and foraging ecology of eastern coyotes in New York State. Progress report
2007-2014, http://frair.weebly.com/uploads/3/1/7/8/31787235/
coyote_progress_report_2014.pdf
Warsen, S.A. (2012) Evolving niche of coyotes in the Adirondack Mountains
of New York: long-term dietary trends and interspecific competition. M.S.
Thesis, SUNY ESF, Syracuse, NY. 90 pp.
Conference presentations
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited presentation). The Wildlife Society Annual Conference, Pittsburgh,
PA.
Seminars, webinars, and other tangible products
Frair, J.L. (2015) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). Cayuga County Federation of Conservation Clubs –
Auburn, NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). Biology Department Seminar Series, University of
Alberta, Edmonton, Alberta, Canada.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). Earth Lecture Series, SUNY ESF, Syracuse, NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). NYS Department of Environmental Conservation Indian
Nations Meeting, SUNY ESF, Syracuse, NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). Safari Club International, Central NY Chapter – Oneonta,
NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). New York State Fish and Wildlife Management Advisory
Board – Pulaski, NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). New York State Conservation Council – Utica, NY.
Frair, J.L. (2014) Top dog? The ecological role of the coyote in the Northeastern
U.S. (invited seminar). American Wildlife Conservation Foundation – Smyrna,
NY.
Leveraged grants
Research for carnivore management on Fort Drum, PI: J. Frair. Source: US
Army Corps of Engineers, $141,000, 2013-2016.